1. Field of the Invention
The present invention relates generally to the recording of data to optical media, and more specifically to a method for enabling multi-session capability in Universal Disk Format™ (UDF) Revision 1.02 environments.
2. Description of the Related Art
As optical media recording technology continues to make substantial advancements, the casual consumer computer user is able to record all kinds, types, and formats of digital data to compact disc (CD), digital video disc (DVD), and the various kinds, types, and formats of optical media. As is well known, there are several types of optical media and associated optical media standards to define structure and format and to ensure compatibility across disparate operating systems, components, and devices. For example, ISO-9660, Joliet, UDF, and other standards for media format all have specific applications relevant to optical media.
The structure and format of data recorded to optical media is generally defined and described in the family of UDF specifications. The Optical Storage Technology Association (OSTA) has developed and implemented the UDF to enable file interchange among different operating systems and environments. In general, UDF was developed to implement ISO/IEC 13346 (also known as ECMA 167). Whereas ISO/IEC 13346 is a broad, general standard for storing information on any media, the UDF specifically provides a standard for recording data to a plurality of recordable and rewritable optical media including CD-ROM CD-Recordable (CD-R) and CD-Rewritable (CD-RW) as well as DVD-ROM, DVD-R, DVD-RW, DVD+R, DVD+RW, double density media, multi-layered media, and others. Although terms such as “operating system,” and the process of recording data suggest a computer system environment, it should be appreciated that UDF is applicable to and defines the format for consumer CD audio devices for home and mobile audio systems, consumer DVD devices for both home and mobile DVD audio/visual systems, in addition to the many and varied computer system environments.
The UDF specification includes a number of revisions, some of which were developed and released to capture and implement standards for emerging and developing optical media technologies. By way of example, UDF Revision 1.02 includes standards and formats for DVD devices, UDF Revision 1.50 includes standards and formats for defect management and packet writing, UDF Revision 2.0 includes standards and formats intended to supercede Revision 1.50, and adds standards and formats for streaming and improved security control for optical media, and UDF Revision 2.01 includes standards and formats to update Revision 2.0, and adds standards and formats for real time files. It should be anticipated that, as additional technologies and advancements in optical media are developed and released, the UDF will continue to evolve, and additional revisions will be released.
Multi-session and multi-border recording to optical media is an example of one advancement in optical media technology that was captured in the UDF during the periodic revision cycle. Prior to UDF Revision 1.50, no multi-session or multi-border standards or formats were implemented in the UDF. Beginning with UDF Revision 1.50, multi-session and multi-border recording is implemented in UDF. UDF Revision 1.02, however, does not include implementation of multi-session or multi-border recording, and therefore DVD devices compliant with UDF Revision 1.02 do not support multi-session or multi-border optical media. Consumer DVD devices such as, by way of example, DVD players used with television sets or audio/visual systems are generally UDF Revision 1.02 compliant, and therefore do not support or recognize multi-session or multi-border optical media. Generally, if a multi-session or multi-border DVD is inserted into a UDF Revision 1.02 compliant consumer DVD player, the consumer DVD player will only “see” one session. Typically, only the first session of the multi-session DVD is seen by the consumer DVD player, and therefore only the content of the first session is accessible for viewing.
Generally, consumer computer DVD drives are also UDF Revision 1.02 compliant, and therefore do not support multi-session, multi-border recording As it becomes more and more common for consumers to view and burn DVD media on computers, the compliance of the consumer computer DVD recording device is a relevant consideration. Depending on the operating system found on the consumer computer, the operating system will generally see only the final session of a multi-session media. In a Macintosh™ or a Windows™ NT™ 4.0 and Windows™ 9X™ environment, as of the time of this paper, only the first session is recognized.
In light of the foregoing, what is needed is a method and system of recording DVD optical media that is in accordance with the UDF Revision 1.02, but that can be recorded in multi-session or multi-border, and each session of such recorded media is visible and viewable on UDF Revision 1.02 compliant DVD devices.